A double-decker elevator is known from JP 2007-331871 A. The known elevator comprises a cage frame in which two elevator cages are arranged vertically one above the other. In this regard the two elevator cages each stand on a respective carrier with cable rollers. In addition, provided at the cage frame is a drive unit around which a lifting cable is guided. The lifting cable is on the one hand guided around the cable rollers of the carrier for one elevator cage and on the other hand around the cable rollers of the carrier of the other elevator cage. Through actuation of the lifting cable by means of the drive unit the thus-suspended elevator cages can be raised and lowered relative to the cage frame. The two elevator cages can thereby be differently positioned within the cage frame.
The double-decker elevator known from JP 2007-331871 A can have the disadvantage that the drive unit, which is arranged at the cage frame, demands a relatively large amount of space. In this regard, the drive unit has to have a sufficient performance capability, since different traction forces can act on the lifting cable on the one hand with respect to one elevator cage and on the other hand with respect to the other elevator cage. This is possible, inter alia, due to different loading of the elevator cages. Moreover, high levels of force act on a drive pulley of the drive unit when the two elevator cages have maximum loading. Usually, the drive unit thus has to have a large performance capability in order to be able to accept the arising forces and moments and execute the desired adjustment movement even with maximum or extremely different levels of loading of the elevator cages.